LDX is INTEGER
The leading dimension of the matrix X. LDX >= max(1,N1).

XNORM

XNORM is DOUBLE PRECISION
On exit, XNORM is the infinity-norm of the solution.

INFO

INFO is INTEGER
On exit, INFO is set to
0: successful exit.
1: TL and TR have too close eigenvalues, so TL or
TR is perturbed to get a nonsingular equation.
NOTE: In the interests of speed, this routine does not
check the inputs for errors.